Improving logging of FTP transfer failures (3rd)

(cherry picked from commit 15fe4d914c720c1e1430ff65e102b36b4483ac86)

Source commit: c77590d5b52b3ffa859b40a9d528f81e3221d11e

source/filezilla/FtpControlSocket.cpp

@@ -2777,6 +2777,14 @@ void CFtpControlSocket::FileTransfer(t_transferfile *transferfile/*=0*/,BOOL bFi
         return;
       else
       {
+        if (nError)
+        {
+          LogMessage(FZ_LOG_INFO, L"Destroying data socket on error");
+        }
+        else
+        {
+          LogMessage(FZ_LOG_INFO, L"Destroying data socket after transfer completed");
+        }
         delete m_pTransferSocket;
         m_pTransferSocket=0;
       }